EP0247771B1 - Poröses PTFE - Google Patents

Poröses PTFE Download PDF

Info

Publication number
EP0247771B1
EP0247771B1 EP19870304373 EP87304373A EP0247771B1 EP 0247771 B1 EP0247771 B1 EP 0247771B1 EP 19870304373 EP19870304373 EP 19870304373 EP 87304373 A EP87304373 A EP 87304373A EP 0247771 B1 EP0247771 B1 EP 0247771B1
Authority
EP
European Patent Office
Prior art keywords
bar
film
compressive force
granules
plane
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19870304373
Other languages
English (en)
French (fr)
Other versions
EP0247771A1 (de
Inventor
Thomas Ronald Thomas
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BTG International Ltd
Original Assignee
National Research Development Corp UK
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by National Research Development Corp UK filed Critical National Research Development Corp UK
Priority to AT87304373T priority Critical patent/ATE49375T1/de
Publication of EP0247771A1 publication Critical patent/EP0247771A1/de
Application granted granted Critical
Publication of EP0247771B1 publication Critical patent/EP0247771B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
    • B29C67/20—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 for porous or cellular articles, e.g. of foam plastics, coarse-pored
    • B29C67/205—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 for porous or cellular articles, e.g. of foam plastics, coarse-pored comprising surface fusion, and bonding of particles to form voids, e.g. sintering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/006—Pressing and sintering powders, granules or fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/34—Auxiliary operations
    • B29C44/36—Feeding the material to be shaped
    • B29C44/38—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length
    • B29C44/44—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length in solid form
    • B29C44/445—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length in solid form in the form of expandable granules, particles or beads
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
    • B29C67/02—Moulding by agglomerating
    • B29C67/04—Sintering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2793/00—Shaping techniques involving a cutting or machining operation
    • B29C2793/009—Shaping techniques involving a cutting or machining operation after shaping
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
    • B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
    • B29K2027/18—PTFE, i.e. polytetrafluoroethylene, e.g. ePTFE, i.e. expanded polytetrafluoroethylene
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/04—Condition, form or state of moulded material or of the material to be shaped cellular or porous
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/25—Solid
    • B29K2105/251—Particles, powder or granules
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S521/00—Synthetic resins or natural rubbers -- part of the class 520 series
    • Y10S521/919—Sintered product
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
    • Y10T156/10—Methods of surface bonding and/or assembly therefor
    • Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
    • Y10T156/1062—Prior to assembly
    • Y10T156/1075—Prior to assembly of plural laminae from single stock and assembling to each other or to additional lamina
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249978—Voids specified as micro

Definitions

  • This invention relates to porous PTFE and a process of producing same.
  • liquid and gaseous diffusion processes such as plasma phoresis, renal dialysis, desalination of water and blood oxygenation, utilise thin porous membranes as the control element, the non-porous nature of established PTFE products preventing their use in such processes.
  • Most such membranes are manufactured either from cellulose and its derivates, or from such materials as ceramics, asbestos, glass, porcelain, and metals.
  • the membranes produced are relatively mechanical weak, particularly when produced to achieve high flow rates therethrough and often require the addition thereto of mechanical supports.
  • the membranes although mechanically strong, are not as chemically inert as PTFE.
  • Other plastics materials have been used, but these are invariably less chemically inert than PTFE and may also require mechanical support.
  • a substantially cylindrical bar of non-fibrillated, microporous PTFE the pores of which within any cylindrical surface contained within the bar and centred about the centrallongitu- dinal axis thereof are of substantially uniform size and are substantially uniformly distributed within that surface.
  • a film of non-fibrillated, microporous PTFE the pores of which within any plane substantially perpendicular to the thickness of the film are of substantially uniform size and are substantially uniformly distributed within that plane and all such parallel planes.
  • a process for producing a bar of nonfibrillated, microporous PTFE having a substantially cylindrical outer surface thereto comprising the steps of:
  • the process may furter comprise the step of forming a film from the cooled bar the plane of which film is perpendicular to the direction of the radial compressive force whereby the pores within any plane substantially perpendicular to the thickness of the film are of substantially uniform size and are substantially uniformly distributed within that plane and all such parallel planes.
  • the cooled material may be broken up into granules of irregular shape the maximum diameter of which is of the order of 400 microns, preferably 250 microns and more preferably 100 microns.
  • the granules prior to compression, have a bulk density of between 300 and 700 grams/litre.
  • the compressive force is applied radially inwardly of the bar on the substantially cylindrical outer surface thereof.
  • the bar is of substantially annular shape in transverse section and the compressive force is applied radially outwardly of the bar on the substantially cylindrical inner surface thereof.
  • the bar is of substantially annular shape in transverse section and compressive forces are applied both radially inwardly and radially outwardly of the bar on the substantially cylindrical outer and inner surfaces thereof respectively.
  • the compressive force applied to the granulated material may be within the range 40 to 900 kg/cm 2 depending upon the nature of the material and the desired porosity and strength of the resultant product.
  • the microcrystalline melting point of untreated PTFE powder is about 340°C, and the temperature of the initially heated powder is preferably within a few degrees of this value, either above or below this value, typically within the range of 300°C to 360°C.
  • the microcrystalline melting point of the material will have fallen, and the second heat treatment following compression of the granulated material is carried out to a temperature above this value, typically to about 380°C when expansion of the material occures predominantly in a direction opposite to that of the previously applied pressure.
  • Cooling of the material after both the initial and second heating treatments may be carried out slowly or by quenching depending upon the desired properties of the end product.
  • a film of material may be produced from the cylindrical bar by subjecting the bar to a knifing or skiving treatment with a blade extending parallel with the central longitudinal axis of the bar, while the film of material so formed may be laminated to a sheet of hydrophilic material.
  • PTFE powders are supplied in a range of particle sizes and shapes ranging from small, irregularly shaped particles of up to perhaps 60 microns in diameter, to larger substantially spherical particles of several hundred microns in diameter.
  • the preferred particles for treatment in accordance with the process of the invention are the smaller particles of previously untreated PTFE of between 0.20 and 60 microns in diameter and of irregular shape.
  • a quantity of such material is carefully disaglomer- ated by means of a vibrating seive technique and is then poured onto a suitable tray.
  • the powder is then heated to a temperature close to its microcrystalline melting point of about 340°C, typically to a temperature within a few degrees above or below this value, for example between 320°C and 360°C, resulting in the individual particles of the material not fusing completely together but remaining compressible.
  • This can be contrasted with normal sintering of PTFE which is carried out well above said melting point, typically at a temperature of about 380°C, with the result that the particles of the material coalesce into a substantially translucent gel.
  • the heated material is cooled in a controlled manner, either slowly or by quenching, the rate of cooling influencing the properties of the final product.
  • the resultant relatively soft mass is then broken up into granules by any one of various maceration techniques and, before further processing, may be seived into fractions of different granule sizes.
  • the granule size at this stage has a great bearing on the pore size of the finished material. Processing a fraction of material containing granules within a narrow range of sizes will result in a material having a narrow range of pore sizes therein.
  • a preferred working range of granular sizes is between 100 and 250 microns, although the granules may have a maximum diameter of up to of the order of 400 microns.
  • the granules are of spiky, irregular shape and may have a bulk density of between 300 and 700 grams/litre, preferably between 500 and 600 grams/litre.
  • This granular material is then placed into a compression device comprising a hollow metal cylinder housing a cylindrical flexible rubber sleeve surrounding a central, axially-extending mandrel.
  • the granulated material is placed into the rubber sleeve to surround the mandrel, and fluid under pressure is forced into the annular space between the inner wall of the metal housing and the rubber sleeve.
  • the cylinder of granulated material so formed within the sleeve is thus compressed by a uniform radial force applied thereto by way of the rubber sleeve over the whole of the surface area of the sleeve, the pressures involved typically being up to 900 kg/cm 2.
  • the cylinder of compressed granular material is removed from the compression device and, after this compression stage, retains a 'plastic memory' of its structure prior to compression, the microcrystalline melting point of the material having fallen to, typically, about 327°C as a result of the initial heat treatment.
  • the cylinder of granular material is then placed in an oven and is again heated, this time to a temperature well above its current microcrystalline melting point, typically to about 380°C. During this heating stage, the granules fuse together and a large expansion of the material occurs predominantly in a direction opposite to that of the applied pressure during compression - i.e. radially outwardly - with some expansion in the axial direction also.
  • Cooling of the material is then effected in a controlled manner either slowly or by quenching dependent upon the desired properties of the resultant product, quenching resulting in a more porous material than slow cooling.
  • a cylinder of non-fibrillated microporous PTFE in which the nodes of material merge or fuse into one another to define a matrix of pores which, in any cylindrical surface within the material and centred about the central longitudinal axis of the cylinder, are of uniform size and are uniformly distributed in that surface and in any concentric surface.
  • the cylinder of material is skived into a continuous thin film by means of a knife-blade extending axially of the cylinder and co-acting substantially tangentially with the external surface of the cylinder as it is rotated on a central mandrel.
  • the preferred thickness of the films of material according to the invention falls within the range of 50 microns to 200 microns, while the preferred sizes of the pores may range from less than one micron to up to about 10 microns.
  • the nodes of PTFE are also interconnected throughout the tickness of the film to define a complex three-dimensional matrix with much larger pore diameters and relatively non-uniform distribution of pores in planes parallel with the thickness of the film - i.e. perpendicular to the main plane of the film.
  • the material of the invention differs significantly from axially fibrillated material which is necessarily relatively weak in one plane and is therefore prone to easy and undesirable deformation.
  • material according to the invention combines porosity with strength, and shows excellent uniformity of pore size, with water vapour transmission values up to about 20,000 grams / 24 hours / square metre.
  • the material of the invention therefore has ideal application in, for example, liquid and gaseous diffusion and filtration processes, as well as in the textile industry.
  • a further indication of the strength of the porous material according to the invention is achieved by forcing mercury into the pores of the material under gradually increasing pressure, it being observed that the mercury occupies a cumulative volume within the material, and that, on slow release of the pressure, the mercury exudes therefrom with a lag or hysteresis.
  • the test illustrates that the material retains its internal structure despite the presence of the mercury under pressure, and this can be compared with the reaction of axially-fibrillated PTFE to the same test, such material giving up all the mercury immediately on release of the pressure even if said pressure is relatively low and illustrating that the internal pore structure is easily destroyed.
  • the surface morphology of the non-fibrillated, microporous PTFE of the invention is such as to allow adhesion to a wide range of other surfaces without the usual surface preparation for normal, non-porous PTFE.
  • the material can be vulcanised to substrates without the use of adhesives, while, in the textile field, the material in this film form can be laminated to one or more sheets of textile material such as polyester.
  • solids may be deposited within the porous material by absorbtion of solutions, said solid material subsequently being precipitated within the body of the matrix to provide electrically-conducting characteristics to the material.
  • non-fibrillated, microporus PTFE may be varied somewhat from that detailed above.
  • a radially-inwardly directed compressive force could be applied within the hollow cylindrical interior of the mass of granular material.
  • the solid central mandrel of the above- detailed compression device is replaced by a further flexible rubber sleeve centrally within the granular material, the outer surface of the sleeve engaging the granular material and to the hollow interior of which is supplied fluid under pressure whereby the required, radially-outwardly directed compressive force is applied to the granular material by way of the flexible sleeve.
  • a combination of radially-inwardly directed and radially-outwardly directed compressive forces is particularly useful when substantial quantities of granular material are being treated and the thickness of the annulus of material within the compression device is such that radial forces in one direction only may be dissipated through said thickness.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Organic Insulating Materials (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Laminated Bodies (AREA)
  • Filtering Materials (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Molding Of Porous Articles (AREA)
  • Treatments Of Macromolecular Shaped Articles (AREA)
  • Materials For Medical Uses (AREA)

Claims (16)

1. Im wesentlichen zylindrischer Stab aus mikroporösem PTFE, dadurch gekennzeichnet, daß das Material ungefasert ist und daß die innerhalb jeglicher im Stab enthaltenen und um die Stablängsachse zentrierten Zylinderfläche befindlichen Poren von im wesentlichen einheitlicher Größe und innerhalb dieser Fläche im wesentlichen gleichmäßig verteilt sind.
2. Folie aus mikroporösem PTFE, dadurch gekennzeichnet, daß das Material ungefasert ist und daß die innerhalb jeglicher, im wesentlichen senkrecht zur Foliendicke liegenden Ebene befindlichen Poren von im wesentlichen einheitlicher Größe und innerhalb dieser Ebene sowie in allen Parallelebenen im wesentlichen gleichmäßig verteilt sind.
3. Verfahren zur Herstellung von ungefasertem, mikroporösem PTFE mit einer im wesentlichen zylindrischen Außenfläche, das aus folgenden Schritten besteht:
Bereitstellen eines thermisch und druckmäßig unbehandelten PTFE-Pulvers,
Erwärmen des Pulvers auf eine Temperatur, deren Betrag nahe seines mikrokristallinen Schmelzpunktes liegt,
Abkühlen des thermisch behandelten Materials, Zerkleinern des abgekühlten Materials zu einem Granulat,
Formen des granulierten Materials zu einem Stab mit im wesentlichen zylindrischer Außenfläche,
Komprimieren des Stabes aus granuliertem Material,
Befreien des Stabes von der Kompressionskraft,
Erwärmen des komprimierten granulierten Materials auf eine Temperatur über seinem mikrokristallinen Schmelzpunkt, und
Abkühlen des thermisch behandelten Materials, dadurch gekennzeichnet, daß die Pulverteilchen unregelmäßige Gestalt und einen innerhalb eines vorbestimmten Bereiches liegenden Durchmesser aufweisen, und daß die Kompressionkraft auf den Stab radial über das axiale Gesamtausmaß einer Zylinderfläche des Stabes ausgeübt wird und derart ist, daß bei der darauffolgenden Erwärmung des vorangehend komprimierten granulierten Materials das Material vorwiegend in eine zu derjenigen der Kompressionskraft entgegengesetzte Richtung expandiert und die Granulatkörner unter Bildung eines ungefaserten Materials miteinander verschmelzen, dessen innerhalb jeglicher im Stab enthaltenen und um die Stablängsachse zentrierten Zylinderfläche befindlichen Poren von im wesentlichen einheitlicher Größe und innerhalb dieser Fläche im wesentlichen gleichmäßig verteilt sind.
4. Verfahren nach Anspruch 3, gekennzeichnet durch den weiteren Schritt des Bildes einer Folie aus dem abgekühlten Stab, der Ebene senkrecht zur Richtung der radialen Kompressionskraft verläuft, wodurch die innerhalb jeglicher, im wesentlichen senkrecht zur Foliendicke liegenden Ebenen befindlichen Poren von im wesentlichen einheitlicher Größe und innerhalb dieser Ebene sowie in allen Parallelebenen im wesentlichen gleichmäßig verteilt sind.
5. Verfahren nach Anspruch 3 oder 4, dadurch gekennzeichnet, daß der Durchmesser der Pulverteilchen zwischen 0,20 und 60 µ liegt.
6. Verfahren nach den Ansprüchen 3 bis 5, dadurch gekennzeichnet, daß die Granulatkörner unregelmäßige Gestalt und einen maximalen Durchmesser in der Größenordnung von 400 p aufweisen.
7. Verfahren nach den Ansprüchen 3 bis 5, dadurch gekennzeichnet, daß die Granulatkörner unregelmäßige Gestalt und einen maximalen Durchmesser in der Größenordnung von 250 µ aufweisen.
8. Verfahren nach den Ansprüchen 3 bis 5, dadurch gekennzeichnet, daß die Granulatkörner unregelmäßige Gestalt und einen maximalen Durchmesser in der Größenordnung von 100 aufweisen.
9. Verfahren nach den Ansprüchen 6 bis 8, dadurch gekennzeichnet, daß die Granulatkörner vor der Kompression eine Schüttdichte zwischen 300 und 700 g/I aufweisen.
10. Verfahren nach den Ansprüchen 3 bis 9, dadurch gekennzeichnet, daß die Kompressionskraft auf den Stab radial einwärts auf dessen im wesentlichen zylindrische Außenfläche ausgeübt wird.
11. Verfahren nach den Ansprüchen 3 bis 9, dadurch gekennzeichnet, daß der Stab im Querschnitt im wesentlichen ringförmige Gestalt aufweist, und daß die Kompressionskraft auf den Stab radial auswärts auf dessen im wesentlichen zylindrische Innenfläche ausgeübt wird.
12. Verfahren nach Anspruch 11, dadurch gekennzeichnet, daß auf den Stab auch eine Kompressionskraft radial einwärts seiner im wesentlichen zylindrischen Außenseite ausgeübt wird.
13. Verfahren nach den Ansprüchen 3 bis 12, dadurch gekennzeichnet, daß das granulierte Material mit einem Druck im Bereich von 40 bis 900 kg/cm2 komprimiert wird.
14. Verfahren nach den Ansprüchen 3 bis 13, dadurch gekennzeichnet, daß das Pulver anfänglich auf eine Temperatur im Bereich von 320° C bis 360° C erwärmt wird und daß die zweite Erwärmung bei einer Temperatur in der Größenordnung von 380° C durchgeführt wird.
15. Verfahren nach Anspruch 4 und den hievon abhängigen Ansprüchen, dadurch gekennzeichnet, daß die Folie durch Aufschneiden oder Aufspalten des Materialstabes mit einer Klinge gebildet wird, die parallel zur zentralen Längsachse des Zylinders verläuft.
16. Verfahren nach Anspruch 4 und den hievon abhängigen Ansprüchen, gekennzeichnet durch den weiteren Schritt des Laminierens der derart gebildeten Materialfolie zu einer Bahn hydrophilen Materials.
EP19870304373 1986-05-29 1987-05-18 Poröses PTFE Expired - Lifetime EP0247771B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87304373T ATE49375T1 (de) 1986-05-29 1987-05-18 Poroeses ptfe.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB868613015A GB8613015D0 (en) 1986-05-29 1986-05-29 Porous ptfe
GB8613015 1986-05-29

Publications (2)

Publication Number Publication Date
EP0247771A1 EP0247771A1 (de) 1987-12-02
EP0247771B1 true EP0247771B1 (de) 1990-01-10

Family

ID=10598602

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19870304373 Expired - Lifetime EP0247771B1 (de) 1986-05-29 1987-05-18 Poröses PTFE

Country Status (13)

Country Link
US (2) US5514231A (de)
EP (1) EP0247771B1 (de)
JP (2) JPH0716965B2 (de)
AT (1) ATE49375T1 (de)
AU (1) AU607701B2 (de)
CA (1) CA1318090C (de)
DE (1) DE3761358D1 (de)
DK (1) DK172678B1 (de)
ES (1) ES2013630B3 (de)
FI (1) FI93708C (de)
GB (2) GB8613015D0 (de)
IE (1) IE60288B1 (de)
PT (1) PT84977B (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19851239C5 (de) * 1998-11-06 2013-11-07 Aesculap Ag Verwendung einer flächigen Filterschicht

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8613015D0 (en) * 1986-05-29 1986-07-02 Thomas T R Porous ptfe
JPH0737895B2 (ja) * 1988-12-16 1995-04-26 ジューキ株式会社 直接描画方法
JPH0795623B2 (ja) * 1989-05-12 1995-10-11 ジューキ株式会社 直接描画装置における基板表面計測方法
US5677031A (en) * 1990-03-31 1997-10-14 W. L. Gore & Associates, Inc. Porous PTFE structures
GB9007304D0 (en) * 1990-03-31 1990-05-30 Gore W L & Ass Uk Filter element
GB9113350D0 (en) * 1991-06-20 1991-08-07 Thomas Thomas Ronald Asymmetric/anisotropic fluoropolymer membrane manufacture
US5773098A (en) * 1991-06-20 1998-06-30 British Technology Group, Ltd. Applying a fluoropolymer film to a body
GB9405518D0 (en) * 1994-03-21 1994-05-04 Mupor Ltd Porous metal composite body
JP3697315B2 (ja) * 1996-05-13 2005-09-21 松下電器産業株式会社 接着剤塗布装置
US6277464B1 (en) 1997-05-16 2001-08-21 Pall Corporation Polymeric integral net
CA2710960A1 (en) * 2000-11-22 2002-05-30 Bard Peripheral Vascular, Inc. Method for producing a single layer high density expanded polytetrafluoroethylene tube
US6790213B2 (en) * 2002-01-07 2004-09-14 C.R. Bard, Inc. Implantable prosthesis
WO2005042628A1 (en) * 2003-11-03 2005-05-12 Porex Corporation Sintered porous high melt-flow index materials and methods of making same
US7498392B2 (en) * 2005-01-19 2009-03-03 Nelson Kevin G Methods and compositions for dielectric materials
RU2414349C2 (ru) * 2008-01-29 2011-03-20 Виктор Германович Зотин Способ производства деталей из термореактивных, термопластичных масс, обладающих свойством хладотекучести
US8926840B2 (en) 2008-03-18 2015-01-06 Rubbermaid Incorporated Drinking container and filter assembly
US9072586B2 (en) 2008-10-03 2015-07-07 C.R. Bard, Inc. Implantable prosthesis
US8628843B2 (en) * 2008-10-24 2014-01-14 Porex Corporation Composite PTFE materials and applications thereof

Family Cites Families (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2400091A (en) * 1944-09-20 1946-05-14 Du Pont Molding process
GB831326A (en) * 1955-12-22 1960-03-30 Bound Brook Bearings Ltd Fluid-permeable element
GB853030A (en) * 1957-05-14 1960-11-02 Bound Brook Bearings Ltd Method of forming a uniformly, or substantially uniformly, porous body of p.t.f.e.
US3015855A (en) * 1958-02-01 1962-01-09 Merkel Ewald Method of and device for making hollow bodies
BE606897A (de) * 1960-08-18 1900-01-01
GB943624A (en) * 1960-10-05 1963-12-04 Doulton & Co Ltd Permeable plastic materials
FR1501835A (fr) * 1966-09-22 1967-11-18 Wonder Piles Perfectionnements aux membranes étanches aux liquides mais perméables aux gaz, notamment pour piles et accumulateurs
DE1769595C3 (de) * 1968-06-12 1975-07-17 Robert Bosch Gmbh, 7000 Stuttgart Verfahren zur Herstellung von gasdurchlässigen, hydrophoben Folien aus fluorhaltigen Polymeren für elektrochemische Zellen, insbesondere Brennstoffzellen
DE2005394A1 (de) * 1970-02-06 1971-08-26 Bosch Gmbh Robert Verfahren zur Herstellung von gas durchlassigen, elektrolytundurchlassigen Folien fur elektrochemische Zellen, ins besondere Brennstoffzellen
SE392582B (sv) * 1970-05-21 1977-04-04 Gore & Ass Forfarande vid framstellning av ett porost material, genom expandering och streckning av en tetrafluoretenpolymer framstelld i ett pastabildande strengsprutningsforfarande
GB1331775A (en) * 1970-07-09 1973-09-26 Ici Ltd Porous tetrafluoroethylene polymer tape
US3753566A (en) * 1970-09-12 1973-08-21 Maruko Co Ltd Cassette adapter
SE387886B (sv) * 1973-03-19 1976-09-20 Sumitomo Electric Industries Forfarande for framstellning av en poros film av polytetrafluoreten
SU468796A1 (ru) * 1973-04-20 1975-04-30 Предприятие П/Я А-1385 Способ получени фильтрующей политетрафторэтиленовой пленки
FR2374153A1 (fr) * 1976-12-20 1978-07-13 Ici Ltd Procede pour la production d'objets en polytetrafluorethylene poreux
US4194041A (en) * 1978-06-29 1980-03-18 W. L. Gore & Associates, Inc. Waterproof laminate
US4344999A (en) * 1980-04-22 1982-08-17 W. L. Gore & Associates, Inc. Breathable laminate
US4302496A (en) * 1980-10-21 1981-11-24 Albany International Corp. Composite waterproof and flame resistant fabrics
FI77698C (fi) * 1982-11-19 1989-04-10 Gore & Ass Polytetrafluoretenlaminat foer skodon.
US4443511A (en) * 1982-11-19 1984-04-17 W. L. Gore & Associates, Inc. Elastomeric waterproof laminate
EP0172750A3 (de) * 1984-08-22 1987-03-18 E.I. Du Pont De Nemours And Company Poröse Strukturen
JPS6191229A (ja) * 1984-10-11 1986-05-09 Daikin Ind Ltd フツ素樹脂発泡体の製法
GB8613015D0 (en) * 1986-05-29 1986-07-02 Thomas T R Porous ptfe

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19851239C5 (de) * 1998-11-06 2013-11-07 Aesculap Ag Verwendung einer flächigen Filterschicht

Also Published As

Publication number Publication date
CA1318090C (en) 1993-05-25
FI872356L (fi) 1987-11-30
AU7349387A (en) 1987-12-03
EP0247771A1 (de) 1987-12-02
US5677047A (en) 1997-10-14
DE3761358D1 (de) 1990-02-15
ES2013630B3 (es) 1990-05-16
AU607701B2 (en) 1991-03-14
JP2504703B2 (ja) 1996-06-05
DK257387A (da) 1987-11-30
JPS6354237A (ja) 1988-03-08
GB2193214A (en) 1988-02-03
PT84977A (en) 1987-06-01
IE60288B1 (en) 1994-06-29
FI93708C (fi) 1995-05-26
GB8613015D0 (en) 1986-07-02
US5514231A (en) 1996-05-07
IE871392L (en) 1987-11-29
FI872356A0 (fi) 1987-05-27
JPH0716965B2 (ja) 1995-03-01
JPH07138395A (ja) 1995-05-30
GB8711665D0 (en) 1987-06-24
DK172678B1 (da) 1999-05-17
PT84977B (en) 1989-07-28
FI93708B (fi) 1995-02-15
ATE49375T1 (de) 1990-01-15
DK257387D0 (da) 1987-05-21

Similar Documents

Publication Publication Date Title
EP0247771B1 (de) Poröses PTFE
US4707314A (en) Process for producing polytetrafluoroethylene porous films
CA1057014A (en) Porous products and process therefor
US3953566A (en) Process for producing porous products
US5275766A (en) Method for making semi-permeable polymer membranes
US4710331A (en) Process for the production of polytetrafluoroethylene porous membranes
JPH03179038A (ja) ポリテトラフルオロエチレン複層多孔膜の製造方法
EP0188812B1 (de) Verfahren zur Oberflächenbehandlung einer dünnen porösen Folie
JPH0533650B2 (de)
JPH0413770A (ja) 絶縁材料及びその製造方法
JP3360286B2 (ja) 多孔質ポリテトラフルオロエチレン及び製造法
KR102641991B1 (ko) 불소계 수지 다공성 막의 제조방법 및 그 방법에 의해 제조된 불소계 수지 다공성 막
JPS6166730A (ja) ポリテトラフルオロエチレン樹脂多孔質体の製造方法
EP0507286B1 (de) Formverfahren zur Herstellung poröser Polytetrafluoroethylen-Gegenstände
JPH0391544A (ja) 四フッ化エチレン樹脂多孔質体
JP3456284B2 (ja) 多孔質四弗化エチレン樹脂積層体とその製造方法
US4942092A (en) Extruded porous articles of polyimide and continuous preparation of the same
JPH1135716A (ja) ポリテトラフルオロエチレン製多孔質膜の製造方法
JP3462638B2 (ja) 多孔質シート
JPS60104319A (ja) ポリテトラフルオロエチレン多孔質体及びその製造方法
JPS63236621A (ja) テトラフルオルエチレンの重合した単位より実質的に構成される予備成形体から成形体を製造する方法
JP2780113B2 (ja) ポリテトラフルオロエチレン多孔質体の製造方法
JPS6157328A (ja) ポリテトラフルオロエチレン多孔質体の製造法
JP2801658B2 (ja) ポリテトラフルオロエチレン多孔質体およびその製造方法
JPS60179236A (ja) 四フツ化エチレン樹脂多孔質体の製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE ES FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19880128

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: NATIONAL RESEARCH DEVELOPMENT CORPORATION

17Q First examination report despatched

Effective date: 19880921

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE ES FR GB IT LI NL SE

REF Corresponds to:

Ref document number: 49375

Country of ref document: AT

Date of ref document: 19900115

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3761358

Country of ref document: DE

Date of ref document: 19900215

ITF It: translation for a ep patent filed
ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

RIN2 Information on inventor provided after grant (corrected)

Free format text: THOMAS, THOMAS RONALD

26N No opposition filed
ITTA It: last paid annual fee
REG Reference to a national code

Ref country code: GB

Ref legal event code: 732

ITPR It: changes in ownership of a european patent

Owner name: CESSIONE;BRITISH TECHNOLOGY GROUP LIMITED

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

REG Reference to a national code

Ref country code: CH

Ref legal event code: PUE

Owner name: BRITISH TECHNOLOGY GROUP LTD

NLS Nl: assignments of ep-patents

Owner name: BRITISH TECHNOLOGY GROUP LTD TE LONDEN, GROOT-BRIT

REG Reference to a national code

Ref country code: ES

Ref legal event code: PC2A

Owner name: BRITISH TECHNOLOGY GROUP LIMITED

EAL Se: european patent in force in sweden

Ref document number: 87304373.1

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20060503

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20060505

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20060511

Year of fee payment: 20

Ref country code: AT

Payment date: 20060511

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20060515

Year of fee payment: 20

Ref country code: CH

Payment date: 20060515

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20060517

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20060531

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20060621

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20060712

Year of fee payment: 20

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20070518

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20070519

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

NLV7 Nl: ceased due to reaching the maximum lifetime of a patent

Effective date: 20070518

EUG Se: european patent has lapsed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20070519

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20070517

BE20 Be: patent expired

Owner name: *BRITISH TECHNOLOGY GROUP LTD

Effective date: 20070518